Process of separating mercury from poor ores by electrolysis.



UNITED srn'rns PATENT QFFICE.

BELA SZILARD, OF PARIS, FRANCE, ASSIGNOR TO SAID BELB. SZILARD AND HENRY BERGERAT,

OF PARIS, FRANCE.

PROCESS OF SEPARATING MERCURY FROM POOR ORES BY ELECTROLYSIS.

No Drawing.

To all whom it may concern:

Be it known that I, Brim b'zimnn, cheniist, resident of Paris, France, have invented new and useful Improvements in Processes for Separating Mercury from Poor Ores by Electrolysis. which improvements are fully set fortli in the following specification.

Hitherto mercury has been obtained .only by a method of metallurgical treatment, which process was economical only with rich ores.

For extracting mercury from poor ores, it has already been suggested to lixiviate the ores y means of sodium sulfid, but the process in question was never worked, owing to the high cost of the substance in q'uestion, and partly for the reason that mercury dissolved in a solution of sodium sulfid cannot be submitted to electrolysis without a considerable loss of current. In fact, in the course of electrolysis there take place secondary reactions which absorb a considerable portion of.

the current.

The process according to this invention enables electrolysis to be effected in an easy and cheap manner. Tghis process consists in using a lixiriating agent, a mixture consisting of a hot solution of sodium chlorid and of calcium sulfid obtained as a byproduct in the manufacture of soda by the Leblanc process, or oi other calcium sulfide. rendered alkaline by oxid of calcium. The

tepid mixture is added to the finely crushed ores and after having left it to stand for two days, a current of hot air is sent through this mixture from below. The hot air reheats to a certain extent the solution, which facilitates the dissolving of the mercury, and moreover, owing to the mixing action of the said air, it serves the same purpose. But the most important object of the hot air current consists in it converting calcium sulfid into thiosulfate of calcium which is deposited with the ores. The liquid discharged contains mercury not in the form of a sulfid, but in the form of a double salt solution (mercury and sodium chlorid) which can be submitted to electrolysis with an insignificant loss of current, that is to say, practically speaking, without loss of current. -With this process, a portion of any silver that may also be contained, is also dissolved.

In order to separate mercury from any silver that may be there, it is possible to use Specification of Letters Patent.

Application'filed June 22, 19 10.

Patented Jan. 3, 1911.

Serial No. 568,296.

in a well known manner suitable metal plates instead of the electric current. It must be further pointed out that lixiviation' can be eiiected more rapidly and with a maximum effect in an autoclave boiler at a pressure of atmospheres and at a suitable temperature.

Claim.

l. The herein described process for recovering mercury from poor ores, which comprises treating finely divided ore with a lixiviating agent comprising a mixed solution of sodium chlorid and calcium sultid, and then subjecting the solution to electrolytic action.

2. The herein described process for recovering mercury from poor ores, which comprises mixing tinely divided ore with a lixiviating agent comprising a combined solution of sodium chlorid and calcium sulfid, allowing the mixture to stand .for a suitable length of time, then blowing a current of heated air through the mixture, and finally drawing oil the solution and separating the mercury therefrom.

Theherein described process of recovering mercury from poor ores, which comprises; first, mixing the finely crushed Ore with a lixiviating agent comprising a com-. bined solution of sodium chlorid and calcium sulfid; second, allowing such mixture to blowing through said mixture a current of heatedair, whereby the calcium sulfid is oxidized; and fourth, drawing off the st lution and subjecting it to electrolytic action.

4. The herein described process of recovering mercury from poor ores, which comprises; first, mixing. the finely crushed ore ing witnesses.

. BELA'SZILAR-D. lVitnesses GASTON Dnaroon'r,

H; C. Coxn.

stand for a suitable length of time; third, 

